Comparison of sensitivities of American college of rheumatology and systemic lupus international collaborating clinics classification criteria in childhood-onset systemic lupus erythematosus

Abstract

Objective. Currently there are 2 different classification criteria for systemic lupus erythematosus (SLE): American College of Rheumatology (ACR) and Systemic Lupus International Collaborating Clinics (SLICC). The aim of this study was to compare the sensitivities of ACR and SLICC criteria in childhood-onset SLE (cSLE) using a large, multiethnic cohort. Methods. We conducted a retrospective study of 722 patients diagnosed with cSLE at The Hospital for Sick Children (SickKids). Prospectively collected data from SickKids' Lupus Database were reviewed/validated against medical records prior to ACR and SLICC scoring based on cumulative symptoms up to the last visit. Sensitivities were compared using McNemar's test. Descriptive statistics were used to identify SLE features unique to each set of criteria and autoantibodies not included in either. Results. ACR and SLICC sensitivities were as follows: 92.4% and 96.3% overall (p = 0.001); 82.5% and 91.3% (p = 0.01) in those scored ≤ 1 year from diagnosis; 92.7% and 97.9% (p = 0.02) in those scored 2-3 years from diagnosis. Forty-eight of 55 (87.3%) patients who did not meet ACR criteria met SLICC criteria through SLICC-specific criterion or renal biopsy. Twenty of 27 (74.1%) patients who did not meet SLICC criteria met ACR criteria as a result of photosensitivity (73.9%) and ACR lymphopenia criteria (26.1%). Six of 7 patients (85.7%) who were clinically diagnosed with cSLE but did not meet either SLICC or ACR criteria had anti-Ro antibodies. Conclusion. SLICC criteria were significantly more sensitive than ACR criteria in cSLE classification, especially early in the disease course. Because of the extreme rarity of primary Sjögren syndrome in children, one may consider adding anti-Ro antibodies to the classification criteria for cSLE because they are present in ~40% of patents with cSLE.